Process of electrolytic deposition of metals from solutions.



N. V. HYBINBTTB. PROOEss OF ELBOTROLYTIO DBPOSITION OP METALS FROMSOLUTIONS. APPLICATION FILED MAY Z2, 1913.

1,123,299. Patented Jan.5,1915.

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changes as can be transmitted through the UNITED STATES IITENT OFFICE.

NOAK VICTOR HYBINETTE, OF CHRISTIANIA, NORWAY.

PROCESS OF ELECTROLYTIC DEPOSITION OF METALS FROM SOLUTIONS.

Application filed May 22, 1913.

To aZZ whom it may concern Be it known that I, NOAK VICTOR HYBI- NETTE,a Subj ect of the King of Norway, residing at Christiania, Norway, haveinvented certain new and useful Improvements in Processes of'Electrolytic Deposition .of Metals from Solutions; and I dohereby'declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to make and use the same.

This invention has for its object a process of electrolyzing coppersolutions containing iron.

In processes of leaching and electrolysis for the recovery of copperfrom ore, where at the same time iron is present in the solution, it hasbeen necessary to reduce the iron in the solution to the ferrous statebefore plating, and such reduction has involved difficulties.

I have now found a novel way to obtain plating of copper without firstreducing the iron to the ferrous state. I make use of a diaphragm,separating the cathode from the anode. This diaphragm is so open andeasily penetrated as to be more in the nature of a filter than adiaphragm in the real sense of that Word. T he apparatus described in U.S. Patent No. 1,052,256, dated February 14, i913, is preferably used. Imaintain a continuous flow of solution through the cell on the anodeside only, and the solution on the cathode side can only be affected by'such filter by reason of diffusion of changes in specific gravity. Thesolution on both sides of the diaphragm may to begin with contain gr.iron as ferrous sulfate, 40 gr. iron as ferric sulfate, 40 gr. copper assulfate and gr. free acid. When now the electric current is turned on,the ferric salts in solution at the cathode are reduced and copperbegins to plate. This causes a decrease of specific gravity of thesolution, and it rises to a level, which is higher on the cathode sidethan on the anode side. .If now the solution on the anode side iscirculated and regenerated by being passed through the copper leachingtanks so as to always be maintained at the said composition, then thesolution on the cathode side will automatically adjust itself to containsay gr. ferrous iron, 5 gr. ferric iron and 20 gr. copper. Copper iscontinually de- Speccation of Letters Patent.

Patented Jan. 5,1915.

Serial No. 769,209.

posited at the cathode and the solution passing out of the anodecompartment of the cell shows a. corresponding reduction in coppercontents and increase in acidity. If a sufficient amount of ferroussalts are present, part of these are also oxidized. 'Without anyapparent reason copper is entering the cathode compartment, while ferricsalts do not enter and the electric energy is therefore used to depositcopper and not to reduce ferric salts. The reason for this may be, thatthe copper sulfate diffuses through the filter while the iron salts donot diffuse at least not to a noticeable extent, or that certaincurrents are created on account of the different specific gravities,whereby certain reactions are going on in the solution. The reason forthis may also be that the ferric sulfate only very slowly passes overtoward the cathode in consequence of diffusion, while the copper movestoward the cathode by diffusion as well as by electrolytic movementthrough the solution.

It is natural, that the speed, at which the copper is plated, must bekept in reasonable relation to the speed with which the copper can comethrough the filter, and this again is dependent upon the concentrationof copper in the anode solution.

With the concentration of solution now mentioned I use a density of l0amperes to the square foot and obtain an efiiciency of nearly 90%. Thetension is in the neighborhood of 3 volts.

Inthe accompanying drawing a cell for use 1n carrying out the presentprocess is diagrammatically illustrated.

In this drawing A is the electrolytic vat containing the electrolyte andthe various parts of the cell.

B is the anode, and C the cathode, which latter is inclosed in adiaphragm bag cornposed of a double-walled leaden screen D secured to aWooden frame K and having a filling of asbestos or other suitablefibrous material between the walls.

F is the inlet for the electrolyte, and G the outlet.

I claim:

-l. The process of electrolytic deposition of metals from solutionscontaining besides the metal to be recovered also considerablequantities of ferric salts; which consists in circulating the solutionto be electrolyzed through the anode side of an electrolytic cell,whereby the metal to be recovered passes to the cathode Without theelectrolyte being circulated through the cathode chamber.

2. The process of electrolytic deposition of metals from solutionscontaining beside the metal to berecovered also considerable quantitiesof ferrie salts; Which'comprises circulating said solution-through theanode chamber While preventing-circulation from the anode chamber to thecathode chamber and maintaining diiusion" therebetween, the

diffusion rate 'of the' matar-to be deposited' being greater than thediffusion rate of the` erric salt in said solution, passing an e1ec`tric current through the solution from the.

anode to the cathode and depositing the metal to be recovered at thecathode.

In testimony that I claim the foregoing as my invention, I have signedmy name in presence of two subscribinff Witnesses.

NOAK VICTOR YBINETTE. [Witnesses:

' M. E. GUTroRENsEN,

xRUTH LINDsTRM.

